Propellors are one of the best wreck features to find underwater. They’re nice and recognisable and they always hang out in the same place. If they’re still somewhere down there, they’re usually fairly easy to find and identify. And the bigger the ship wreck, the bigger the propellor, right up to some very impressive sizes. There’s something about swimming between massive blades that could have quite easily chopped you up into little bits while in operation.
A lot of the regularly dived wrecks out of Melbourne were scuttled and in some cases had their props removed before heading down to the ocean floor. Whereas the Truk shipwrecks went down with everything on board, so whether the propellors are present or not is more a question of where the bombs hit. From a photographic perspective it was also a question of one propellor or two. As you can see in the first photo here of the Heian Maru, two propellors made life a lot easier. One propellor set-ups could be found poked between massive hull plates, like the above photo of the prop of the Kiyosumi. With a bit of encrusting coral in the way, it’s hard to visualise the propellor distinct from the surrounding ship.
The dual prop ships required very clear water to get both sets of blades in one shot. On the other hand they lend themselves nicely to single shots. The Heian Maru lies on her port side, and this port side prop is down in the dark on the seabed, shaded by the hull. The largest wreck in the Lagoon at over 160m long and 11,615 tonnes, she was a luxury passenger liner before being converted to military use as a submarine tender. These two massive propellors gave her a cruising speed of 15 knots.
This photo shows a prop built for a completely different purpose. The bracing and the pitch of the three blades give some indication – the Fumizuki was built for speed. This Japanese destroyer was the only one we dived on this trip and it contrasted starkly with the large holds and spacious interiors of the cargo & supply ships. With a displacement of just over 1,900 tonnes she was narrow and low to the water. She was also capable of a top speed of 34 knots.
Unlike the four bladed props of the cargo ships and the three bladed prop of the Fumizuki, the submarine the I169 appears to have had a five bladed prop. She was on a supply run to Truk after Operation Hailstone when word of an impending American attack had her crew rush to dive. When the sub didn’t surface after the attack was over divers were sent down. They discovered an open valve and flooded control room. Unable to access the controls to lift her, her crew was reduced to tapping on the hull to communicate with the divers. After several days of unsuccessful attempts to raise her the tapping inside had ceased. The Japanese Navy used depth charges to destroy the stern, presumably to protect their technology from future attempts to raise her. Half of this prop is one of the few easily recognisable bits in the debris on the sand.
For something a little bit different there’s the plane propellors. These are from the Emily, a sea plane who now sits on the sand in 13m. She landed upsidedown with her landing gear sticking up towards the surface. Her four engines are no longer attached to each wing. The coral is not as quick to grown on the aluminium bodies of the planes but there are a few soft corals making a start on colonising each prop blade. This is in stark contrast to the coral growth on the prop of the Yamagiri Maru in the next photo.